The correct spelling of the word 'did addition' is "dɪd əˈdɪʃən." In this word, the first syllable is pronounced as "dɪd," with the vowel sound "ɪ." The second syllable is pronounced as "əˈdɪʃən," with a schwa sound "ə" followed by the stress on "dɪsh." This word refers to the act of performing the mathematical operation of addition. It is important to spell words correctly to avoid confusion and misunderstanding in communication.